NoOperationMonologHandler incompatible with Monolog\Handler\AbstractProcessingHandler

[a-menshchikov]

Since this commit (Seldaek/monolog@06143b0#diff-
d1d031ebe96084844fb53eb650bc404e) NoOperationMonologHandler doesn't implement AbstractProcessingHandler correctly (doesn't return void). As result there is no way to set jiraLogEnabled = false.

I think this should be fixed ASAP.
Problem is that this breaks backward compatibility and requires PHP 7.0 in composer.json

[lesstif]

@a-menshchikov i was released new major version 2.0.

thanks.